JPS6028077Y2 - Molding equipment for cross-linked polyolefin cable connections - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for forming crosslinked polyolefin cable connections.

Conventionally, when connecting cross-linked polyolefin cables such as cross-linked polyolefin cables, as shown in FIG. Conductor 2, 2
A polyolefin tape 4 containing a crosslinking agent such as dicumyl peroxide is wound around the insulator 3° 3' in a spindle shape, and the wound portion 5 is heated by a heating means such as an infrared lamp 6. , the parts are fused together and crosslinked together.

In recent years, due to the need to reduce the dimensions of cable connections, it has been considered to shorten the length of the exposed portions of the insulators 3, 3' of cross-linked polyolefin cables 1, 1'. Therefore, the heating temperature tends to be high.

As a result, the heat generated when heating the winding portion 5 is not sufficiently dissipated in the exposed portions of the insulators 3, 3', and the exposed portions of the insulators 3, 3' increase in temperature and become soft, and contain the crosslinking agent. Polyolefin tape 4
As shown in FIG. 2, a bump-shaped protrusion 8 is often formed at the boundary with the metal shielding layer 7 made of horizontally wound conductor wire or horizontally wound copper tape. (Parts corresponding to those in FIG. 1 are designated by the same reference numerals.

same as below. ) Therefore, in order to prevent deformation of the insulator, a method has been proposed in which a cooling water passage is provided in the upper and lower molds that are in contact with the insulator, and the tape winding part is heated and molded (Japanese Patent Application Laid-Open No. 49/1989).
This type of heating molding method is suitable when the heating temperature of the winding part is not so high. (Metal shielding layer) When performing heat molding by increasing the heating temperature of the winding part in order to shorten the exposed section of the wire core up to the end position and shorten working time, the problem is that the required cooling effect cannot be obtained. There is.

That is, in a mold in which a cooling water passage is provided in the mold, the heat of the mold generated during hot molding is also conducted to the cooling water passage, which has the disadvantage that the temperature of the coolant increases.

Therefore, if the desired cooling effect cannot be obtained, it is necessary to make design changes to the mold, such as increasing the number of cooling water passages or increasing the inner diameter of the passages. Because of this, separate molds must be manufactured, and special molds must be manufactured for each different cable size, and the work of installing the molds is troublesome, which is economically disadvantageous. There are some difficulties.

The present invention was made to solve these conventional difficulties, and is a method for forming a cross-linked polyolefin cable connection part.
A cross-linkable polyolefin tape-wound layer is wrapped between the insulators on the conductor connection portion of a cross-linked polyolefin cable having a metal shielding layer on the insulator, and the cross-linkable polyolefin tape-wound layer is wrapped by waist heating. a heating device for integrally fusing and crosslinking the polyolefin tape, a tube wound separately from the heating device around the outer periphery of the insulator spanning from the base of the crosslinkable polyolefin tape wound layer to the metal shielding layer; The object of the present invention is to provide a crosslinked polyolefin cable connection part that does not form a hump-like protrusion at the boundary with the metal shielding layer by forming a cooling medium that is forcibly passed through the crosslinked polyolefin cable connection part.

The cross-linked polyolefin cable to which this invention is applied is made of high-density, medium-density, or low-density polyethylene.
dicumyl peroxide, 2,5-dimethyl-2,5-
In addition to cables having a crosslinked polyethylene insulation coating made by heat-crosslinking l-5PHR with a crosslinking peroxide such as di(t-butylperoxy)hexyne-3, silicone-grafted polyethylene and dibutyltin dilaurate are also available. There are cables having a crosslinked silyl-modified polyethylene insulation coating which is crosslinked in the presence of a silanol condensation catalyst such as silanol condensation catalyst.

Examples of the crosslinkable plastic table used in the present invention include a polyethylene tape containing 1 to 5 PHR of the above-mentioned crosslinking peroxide, and a silyl-modified polyethylene tape containing a silanol condensation catalyst.

Therefore, the apparatus for forming a cross-linked polyolefin cable connection part according to the present invention is to form a spindle-shaped cross-linked polyolefin cable 1. a heating device 9 for enveloping a cross-linkable polyolefin tape-wound layer wound around the cross-linkable polyolefin tape-wound layer and fused and cross-linking the cross-linkable polyolefin tape-wound layer together by heating; Tubes 10, 10 are wound around the outer periphery of the insulators 3, 3 spanning the metal shielding layer, separated from the heating device 9, and a cooling medium made of air, water, etc. is forcibly passed through the tubes. It consists of

Note that the heating device 9 should not be a device with a large number of infrared lamps installed around the inner periphery of the container, a band heater, or the like.

The pipe 10.10 is made of a flexible pipe such as a plastic tube or a lead pipe, and is suitably provided with small holes for injecting refrigerant toward the insulator, if necessary.

As is clear from the above explanation, according to the present invention, when connecting a cross-linked polyolefin cable, the insulator at the base of the cross-linkable polyolefin tape wound around the connection part is forcibly cooled. There is no deformation of this part, therefore, when stripping the insulator, the exposed part of the insulator can be shortened and the entire connection part can be made smaller, and the heating temperature can be increased to shorten the connection work time. It is possible.

In addition, compared to the conventional heating molding method, which has cooling water passages in the mold, it is easier to obtain the required cooling effect by adjusting the number of turns of the tube provided on the outer periphery of the cable insulator at the required locations. It has good performance, can be easily applied to cables of different sizes, and is economically advantageous.

Although the above description has been given of an example in which the present invention is applied to a straight connection, the present invention is not limited to such an embodiment, and can also be applied to a Y-branch connection or a terminal connection. It is possible.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing a conventional connection method for a cross-linked polyolefin cable, and Figure 2 shows a protrusion formed near the copper tape shielding layer of the exposed insulator of a cross-linked polyolefin cable by the conventional connection method. The explanatory diagram, FIG. 3, is an explanatory diagram showing an embodiment of the present invention. 1.1'...Crosslinked polyolefin cable, 2
．． 2'...Conductor, 3,3'...Insulator, 4...Polyolefin tape containing crosslinking agent, 6...Infrared lamp, 8... ...Knob-shaped protrusion, 10,10'...Tube.

Claims (1)

[Scope of utility model registration request] A cross-linkable polyolefin tape winding layer wound across the insulators is wrapped over the conductor connection portion of a cross-linked polyolefin cable having a metal shielding layer on the insulator, and the cross-linkable polyolefin tape winding layer is wrapped by heating. a heating device for fusing and cross-linking the layers together; a tube wound separately from the heating device around the outer periphery of the insulator spanning from the base of the crosslinkable polyolefin tape wound layer to the metal shielding layer; 1. An apparatus for forming a cross-linked polyolefin cable joint, comprising: a cooling medium forced to flow into the pipe.